Why does scratching stop the itch?

Itching is an intense and uncomfortable experience - especially if scratching only makes it worse. However, why does scratching make us feel good?

The itching sensation comes from many different causes, allergies, dry weather, or pathogens. In addition, there are many causes of itching, such as burning itch caused by shingles, or itching on the sides of the mouth due to a pinched nerve in the neck, "itching" caused by contact with water, or a rare condition in which the body itches from having too many red blood cells.

In most cases, however, the itch signal is transmitted through the skin, which travels through nerves to the spinal cord. Here, a molecule called natriuretic polypeptide B is produced, which signals the brain to cause itching.

When we scratch, the impact of our fingers on the skin creates a mild pain, overwhelming the itching sensation. From there, distract, make the brain no longer feel itchy. This is why pinching or slapping an itchy spot can also work.

Unfortunately, some of those calming transmitters, including serotonin, can make it easier for the itch signal to return. That's why scratching makes you itch more, and starts a vicious cycle that scientists call the itch-scratch cycle.

The good news is that scientists are learning about this unique itch response, and in the future, we might be able to get rid of the uncontrollable itch for good.